BuildZoom, a company that helps consumers find contractors, released a study on the expansion of American cities over the past 60-plus years.

According to BuildZoom’s chief economist, Dr. Issi Romem, the expansion of cities as a whole hasn’t slowed down. In fact, many are expanding a similar rate seen in the 1950s.

Cities throughout the nation are going through one of two processes: expanding or growing more expensive. Those cities that are becoming more expensive are typically the same ones that are limited to outward expansion by geography.